Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-temperature Detrital Thermochronometry

学术价值：PIS建议使用磷灰石中的(U-Th)/He系统来研究南极半岛中部的折返历史、现代地形的发展和冰川侵蚀的模式。南极半岛自始新世以来一直是冰川，更新世气候变冷被认为抑制了冰川侵蚀，而不是加剧了冰川侵蚀。为了实现这些目标，PI将使用温度计时记录来记录目前的冰川山谷起伏形成的时间和方式。拟议的研究面临的一个挑战是，与温带地区的更新世冰川景观不同，半岛被冰覆盖，不可能直接对基岩表面进行采样。PIS希望通过对半岛主要冰川接地线附近收集的冰川沉积物进行磷灰石(U-Th)/He和4He/3He测量，了解冰川山谷形成的时间和过程。了解南极半岛地貌是如何形成的，对于查明冰川侵蚀机制如何在长时间尺度上运作以及了解冰川如何调节气候变化和造山带物质平衡之间的相互作用非常重要。这项工作解决了南极地球科学中的一个基本问题，即如何推断活跃在冰盖和难以接近的地貌上的地质和地貌过程。广泛的影响：这项提议将把新的研究人员带入南极研究界。拟议中的与英国南极调查研究人员的合作将建立一个国际合作。该项目的成果对其他领域具有辅助意义，并解决了南极地球科学的根本挑战。

Intellectual Merit: The PIs propose to use the (U-Th)/He system in apatite to investigate the exhumation history, development of the present topography, and pattern of glacial erosion in the central Antarctic Peninsula. The Antarctic Peninsula has been glaciated since the Eocene and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. To achieve these goals, the PIs will use a thermochronometric record of when and how the present glacial valley relief formed. A challenge to the proposed research is that, unlike Pleistocene glacial landscapes in temperate areas, the Peninsula is ice-covered and it is not possible to directly sample the bedrock surface. The PIs hope to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. Learning how the Antarctic Peninsula landscape formed is important to discern how the mechanics of glacial erosion operate on long time scales, and to understand how glaciers mediate the interaction between climate change and orogenic mass balance. This work addresses a fundamental question in Antarctic earth science of how to infer geologic and geomorphic processes active on an ice-covered and inaccessible landscape.Broader impacts: This proposal will bring new researchers into the Antarctic research community. A proposed collaboration with British Antarctic Survey researchers will build an international collaboration. The outcomes of this project have ancillary importance to other fields and addresses fundamental challenges in Antarctic Earth Science.